2,255 research outputs found

    Anxiety-like behaviour is regulated independently from sex, mating status, and the sex peptide receptor in Drosophila melanogaster

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    Sex differences in anxiety-related behaviours have been documented in many animals and are notable in human populations. A major goal in behaviour research is to understand why and how sex differences in cognitive-emotional states like anxiety arise and are regulated throughout life. Anxiety allows individuals to detect and respond to threats. Mating is a candidate regulator for anxiety because threats are likely to change, often in sex-specific ways, when individuals shift to a postmating reproductive state. However, we know little about how mating mediates anxiety-related behaviour in males and females, or about how males might influence female anxiety via seminal proteins transferred during mating. To address this gap, we examined anxiety-related behaviour in the fruit fly Drosophila melanogaster, an emerging model animal for anxiety, with respect to sex, mating and sex peptide, a seminal protein known to modulate a host of female postmating responses in fruit flies. We assayed anxiety-like behaviour using the open-field assay to assess individual avoidance of the interior of an arena (‘wall-following’ behaviour). We found sex differences in activity level, but no evidence for sex differences in wall-following behaviour. We found no effects of mating in either sex, or of the presence of the sex peptide receptor in females, on wall following. Our results suggest that anxiety is not one of the cognitive-emotional states regulated by mating and sex peptide in fruit flies, and that researchers need an alternative model for sex differences in anxiety

    Adolescents consider the future differently depending on the domain in question: results of an exploratory study in the United Kingdom

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    The study of Consideration of Future Consequences (CFC) construct has increased substantively in recent years. Underlying these developments is the presumption that consideration of the future is uniform across all domains, and not a domain-specific construct. Building on work undertaken previously, the present study used 30 researcher-derived items to assess the domain specificity of consideration of the future in three large samples of adolescents in the United Kingdom. A psychometrically valid and reliable 18-item scale measuring consideration of the future in four domains emerged. Domain specificity was supported on two levels: a good fitting multidimensional model of CFC; and low to moderate factor correlations for the four domains measured by the 18-item scale. The study suggests that adolescents are considerate of future outcomes to different degrees, depending on the domain, and the implications of this with regard to future research are discussed

    The evolution of sex peptide: sexual conflict, cooperation, and coevolution

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    A central paradigm in evolutionary biology is that the fundamental divergence in the fitness interests of the sexes (‘sexual conflict’) can lead to both the evolution of sex-specific traits that reduce fitness for individuals of the opposite sex, and sexually antagonistic coevolution between the sexes. However, clear examples of traits that evolved in this way – where a single trait in one sex demonstrably depresses the fitness of members of the opposite sex, resulting in antagonistic coevolution – are rare. The Drosophila seminal protein ‘sex peptide’ (SP) is perhaps the most widely cited example of a trait that appears to harm females while benefitting males. Transferred in the ejaculate by males during mating, SP triggers profound and wide-ranging changes in female behaviour and physiology. Early studies reported that the transfer of SP enhances male fitness while depressing female fitness, providing the foundations for the widespread view that SP has evolved to manipulate females for male benefit. Here, we argue that this view is (i) a simplification of a wider body of contradictory empirical research, (ii) narrow with respect to theory describing the origin and maintenance of sexually selected traits, and (iii) hard to reconcile with what we know of the evolutionary history of SP's effects on females. We begin by charting the history of thought regarding SP, both at proximate (its production, function, and mechanism of action) and ultimate (its fitness consequences and evolutionary history) levels, reviewing how studies of SP were central to the development of the field of sexual conflict. We describe a prevailing paradigm for SP's evolution: that SP originated and continues to evolve to manipulate females for male benefit. In contrast to this view, we argue on three grounds that the weight of evidence does not support the view that receipt of SP decreases female fitness: (i) results from studies of SP's impact on female fitness are mixed and more often neutral or positive, with fitness costs emerging only under nutritional extremes; (ii) whether costs from SP are appreciable in wild-living populations remains untested; and (iii) recently described confounds in genetic manipulations of SP raise the possibility that measures of the costs and benefits of SP have been distorted. Beyond SP's fitness effects, comparative and genetic data are also difficult to square with the idea that females suffer fitness costs from SP. Instead, these data – from functional and evolutionary genetics and the neural circuitry of female responses to SP – suggest an evolutionary history involving the evolution of a dedicated SP-sensing apparatus in the female reproductive tract that is likely to have evolved because it benefits females, rather than harms them. We end by exploring theory and evidence that SP benefits females by functioning as a signal of male quality or of sperm receipt and storage (or both). The expanded view of the evolution of SP that we outline recognises the context-dependent and fluctuating roles played by both cooperative and antagonistic selection in the origin and maintenance of reproductive traits

    Henry J. Kaiser Family Foundation; National Alliance of State and Territorial AIDS Directors - National ADAP Monitoring Project Annual Report

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    Based on a survey of AIDS Drug Assistance Programs (ADAPs), which provide prescription drugs to low-income, uninsured, and underinsured HIV/AIDS patients, provides an overview of ADAPs' operations, developments, challenges, and policy and program changes

    Discrete mode laser diodes with ultra narrow linewidth emission <3kHz

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    Ex-facet, free-running ultra-low linewidth (<3 kHz), single mode laser emission is demonstrated using low cost, regrowth-free ridge waveguide discrete mode Fabry-Perot laser diode chips

    Henry J. Kaiser Family Foundation - National ADAP Monitoring Project Annual Report 2007

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    Provides the latest data on state AIDS Drug Assistance Programs (ADAPs), which provide HIV/AIDS-related prescription drugs to low-income, uninsured, and underinsured individuals living with HIV/AIDS

    Job characteristics and mental health for older workers

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    Background: Adverse job characteristics have been linked with increased incidence of depression and anxiety in working populations. However, the association between job characteristics and mental health, in an older working population while controlling for personality traits, is less well known. Aims: To examine the association between job characteristics (job demands and job control) and mental health (depression and anxiety) for older workers while controlling for personality traits. Methods: A sample of workers aged 50-69 years were recruited from a primary health care clinic in Southern Ireland. Job characteristics were measured using the Copenhagen Psychosocial Questionnaire; demands (quantitative and cognitive) and control (influence at work and possibilities for development). Personality traits were measured using the Ten-Item Personality Inventory, depression was measured using the Center for Epidemiological Studies-Depression Scale and anxiety was measured using the Hospital Anxiety and Depression Scale. Descriptive analysis, simple and multiple linear regression analyses were conducted. Results: The final sample size was 1025 with an initial 67% response rate. Multiple linear regression analysis showed job characteristics (in particular, job demands) to be significant positive predictors of symptoms of depression and anxiety. The inverse was true for job control variables and symptoms of depression. Neither possibilities for development nor influence at work were associated with symptoms of anxiety. Conclusions: Our findings indicate that despite potential confounders, higher demands at work can impact the worker's mental health negatively. Reducing job demands and encouraging role development may benefit the mental health of older workers

    Evaluation of Rapid Syphilis Testing Using the Syphilis Health Check in Florida, 2015–2016

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    The Syphilis Health Check (SHC) had low estimated specificity (91.5%) in one Florida county. We investigated use of SHC by a range of Florida publicly-funded programs between 2015 and 2016 to estimate specificity, positive predictive value (PPV), field staff acceptance, and impacts on programmatic outcomes. All reported SHC results were extracted from routinely collected program data. Field staff were surveyed about SHC’s utility. Analyses investigated differences between SHC and traditional syphilis testing outcomes. Of 3,630 SHC results reported, 442 were reactive; 92 (20.8%) had prior diagnoses of syphilis; 7 (1.6%) had no further testing. Of the remaining 343; 158 (46.0%) were confirmed cases, 168 (49.0%) were considered false-positive, and 17 (5.0%) were not cases but not clearly false-positive. Estimated specificity of SHC was 95.0%. Overall, 48.5% of positives became confirmed cases (PPV). PPV varied according to prevalence of syphilis in populations tested. Staff (90%) thought SHC helped identify new cases but expressed concern regarding discordance between reactive SHC and lab-based testing. Programmatic outcomes assessment showed shorter time to treatment and increased numbers of partners tested for the SHC group; these enhanced outcomes may better mitigate the spread of syphilis compared to traditional syphilis testing alone, but more research is needed
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